Electromagnetic brake



H. E. HODGSON ELECTROMAGNETIC BRAKE April 7, 1925.l

Filed April 1,2. 1924 .m T. N. w N l.

' A Troie/VE Y" Patenaa Apr. 7', 192s..

. -1 UNITED s'TATEs PATENT oflFlcE.

HOWARD n. HonasoN, or --ilrIr.wAuI{r.I-z,V wIscoNsIN. AssIcfNoRl To THElcur-1.121?.-

Iu'e. co., -or MILWAUKEE, WISCONSIN, A CORPORATION or wIsooNsIN.

nnnc'rmnAcNETIc :BRAKE Applicatien Med April 12, 1924.` Serial No.705,988.

ticularly applicable to .alternating current solenoid operated brakes.

Brakes of various designs have heretofore been employed including1 brakeshoes having spring meansassociate therewith .for settlng the same and asolenoid for releasing the shoes against the action of suchmeans. The sring means is usually adjustable to vary t e braking pressure and 1nractice it has been found that: if the solenoid is of suiiicientsize torelease the shoes under relatively heavy braking pressures considerabledestructive hammering will "occur in the solenoid if the spring means isadjusted for light braking pressures. Furthermore, the manufacturingcost of brakes as heretofore designed was relatively high due to thefact that it' was.. necessary to employ a short stroke solenoid of lar edimensions.

The present invention has .among its objects to provide a simple,compact and efiicient` brake which will overcome" the aforesaidobjections.

Another object i'sto providea brake having a solenoid for releasingthesame and spring means Vfor efectin setting thereof', such means beingadjusta le for variation of the braking effect without substantialvsolenoid variation' of the load on the throughout itsv entire stroke.

Various other objects and advantages of the invention will hereinafterappear. lThe accompanying drawing illustrates a' brake embodying theinvention whichr will now be described, it being understood that thebrake illustrated is susce tibleA of modiication without departing omthe scope of the appended claims. i v

In the drawing,

Figure l isla side elevational viewof the brake, and

Fig.

2 is al1 end elevational /view tlaereof.J

Referring to Fig. 1, the` same illustrates a drum 1 tosbe secured tothemotor or other device to be braked, 'opposed brake shoes 2 and 3 havinglinings 4 for frictionally engaging said drum and a base 5 havlng avertical arm 6 to which said shoesv are pivotally secured by pins 7.

Thebrake operating means includes a I solenoid 8 having awinding 9carried by a laminated magnet frame 10 and a plunger 11 reciprocablewithin said winding.` Magnet frame 10 is fixed 'to arm 6 'by bolts 12and the plunger 11 is operativel -to an operating'arm 13 by a link'14.Arm- 13 is arranged substantially horizontally below the drum 1 andincludes spaced side members 13a and 13b, the right hand ends of saidmembers .being arranged on opposite sides of the free end of Y ingpivotallyconnected thereto by a pin 15, The left handV end 'of arm13 hasa weight ,member 16 xedbetween the. side members thereof `by a bolt'l?and. downward movement o f the left hand end of said arm is'limconnected brake shoe 3 and bel ited by stops 18 on supporting base 5,Base l 5 also carries an adjustable stop 19 which serves to limitdownward movement of the free end of brake shoe 3 and the right hand endof arm 13.

A rod' 20v is ivotally connected to arm- 13 aty a point a jacent theright hand end thereof by a pin 21 andsaid rod extends upwardly throughan opening in the free end of brake shoe 2. Rod 2O is threadedthroughout substantially its entire length and carries an adjustablestop 22 for en aging the underside of brake s hoe 2. lso @said rod has aspring 23 mounted thereon which is held under compressiony betweencollars 24 and 25 slidable on said rod. Collar 24. bears on the upperside of vbrake shoe 2 while collar 25 is adjustable by a nut 26 to yvary the degree of compression of spring23.

From the foregoing it isapparent` that arm 13 tends to move under -theaction of gravity to a position wherein the left hand -end thereof restsagainst stops 18. Furthermore it is apparent that if spring 2 3 iscolgpressed the same tends to move arm 13 out of engagement with stop 18and .also tends to move the free'ends of brake s hoes2 and 3 towardseach other for setting thereof., The

degree of compression :of s "'ng 23jdeter;' I mines the settlng pressurevof theshoes 2 and 3 on drum 1 and it is apparent that compression ofsaid Ispring to a degree suficient to raisearm 13 out of engagement withstop 18 provides a maximum setting pressure determined by the weight ofarm 13. However, by reducingthe compression of spring 20 .thesetting-pressure can be reduced to a minimum determined by the weight ofthe brake shoes 2 and 3 and the `arm 13.

Stop 22 is adjusted so that upon setting o` the brake shoes the sameslightly clears the underside of brake shoe 2. Upon energization ofsolenoid 8 arm 13 is moved in a clockwise .direction from the shown inthe drawing and after a sllght initial movement of said arm from suchposition stop 22 engages the underside of brake shoe 2 and uponcontinued movement of said arm, vbrake shoes 2 and 3 are moved out otengagement with drum 1. Upon full movement of the solenoid the free endof brake shoe 3 Vrests on stop 19 and it is apparent that by properlyadjusting said stop equalization of the clearance between the brakeshoes and the drum is insured.

It should be noted that with the arts arranged as above described arelatively vlong stroke'solenoid can be employed and it should also benoted that during release of the brake the load on the solenoid issubstantially constant throughout its entire operating range, such loadbeing determined by the weight of arm 13, member 16 andshoe 2. Thesefeatures are especially important where an alternatingcurrent operatingsolenoid is employed since the pull of an alternating current solenoid'is substantially constant throughout its' entire operating range andthe size of the solenoid` required to effect release of the brake islargely dependent upon its stroke. Furthermore, it is apparent that ifthesolenoid is of such size as to provide a slightly greater pull thanthat required to efect release ofthe brake, destructive hammering of.the plunger within the solenoid will be minimized.

As before stated the maximum braking effect is obtained when 'spring 20is adjusted to lift arm 13 out of engagement with stop 18. UnderY suchconditions upon setting of the lbrake arm 13 tends to vrebound under theaction of spring 23. However, this tendency is eliminated throughengagement of said arm` with stop 18.

Stop 22 as before stated normally clears l the underside of brake shoe 2and it is thus necessary to occasionally adjust said stop to compensatefor wear of the linig's on the brake shoes.` However, it should be notedthat such adjustment yeffects .only a very slight variation in theosition of the plunger .whereby sealing t ereof is always insured.

-fally connected to one of7 said l tending to move under the action ofWhat I claim as new and desire to secure by Letters Patent is:

1. The combination with a brake drum and cooperating brake shoes ofaweighted operating arm tending to move under the action o gravitytowards a givenxposition, meansoperatively connecting said arm to saidshoes to provide for release of the latvsaid shoes and movable in anopposite direction for release thereof, a fixed stop for limitingmovement of said arm under the action of gravi-ty, and spring means foreffecting setting of said shoes, said spring means tending to movesaidarm out of engagement with said stop and being ine fective upon aslight initial movement of said arm out of engagement with said stop.

3. The combination with a brake drum and cooperating brake shoes ofoperating means for said shoes including a weighted arm tending to movein one direction under the action of gravity to effect setting of saidshoes and movable in an opposite direction for release thereof, a fixedstop for limiting movement of said arm under the action of gravity,spring `means for effecting setting of said shoes, said spring meanstending to move said arm out of engagement with said stop and beingineffective upon a slight initial movement of said arm out of engagementwith said stop and an operating solenoid connected to said arm.

4. The combination with a brake drum and cooperating `pivoted brakeshoes arranged on opposite sides thereof, of a weighted operating armpivotally connected to one of said brake shoes an'd tending to moveunder the action of gravity to a given position, means connecting saidarm to the other of'said brake shoes and providing for release of saidshoes from said drum upon 'movement of said arm out of said givenposition, a spring associated with said means and tending to move saidarm out of said given position and to eliect setting of said brakeshoes, and a solenoid for moving said arm vout of said given positionfor release of said brake shoes.

5. The combination with a brake drum having opposed pivoted brakeshoesfasso-l 'ciated therewith, oan operatinarm pivotrake shoes llOconnection -between said arm and t gravity to a given position, anoperating e other said connection providof said brake shoes,

Isaid brake shoes upon' ing for release of movement of said arm out .ofsaid given settin of said brake shoes, said arm being unin uenced bysaid spring means upon movement thereof out of said given positionposition, spring means associated with said operating connection tendingto move said arm out ofvsaid given position and to efect and anoperating solenoid associated with said arm to effectrelease of saidbrake shoes.

6. The combination with a brake drum andopposedpivoted brake shoestherefor,

one being arranged above said drum andthe other below same, a weightedoperating armjpivotally connected to the free end of the latter brakeshoe and tending to move under the action of gravity to a givenposition, a member pivotally connected vto said arm, and having a stopassociated therewith for engaging said upper brake shoe, said stop beingnormally out of engagement with said'upper brake shoe and being 'adapted`upon movement of said arm out of said given position to engage the sameand effeet release of both ofsaidbrake shoes, spring means associatedwith said member 'to effect setting of said brake shoes, said meanstending to move said arm out of said given position and being inefectiveupon engagement of said stop with said upper shoe and an operatingsolenoid associated with said arm to effect release of said brake shoes.

7. The combination with a brake drum and cooperating upper and lowerbrake shoes pivoted to one side thereof, a weighted brakeoperating'armivotally connected to @the free end of said ower brake shoeand ternating current operating solenoid fornetic means forl operatinsaid arm.

said arm connected thereto-at a point adj'a- 55 cent the free endthereof.

8. The combination with a brake drum and cooperating upper and lowerbrake shoes of a supporting base having said brakeshoes pivotallyconnected thereto at one side of said drum, a brake operating armpivotally connected to the free end of said lower brake shoe and tending'to move downwardly under the 4action of gravity, a member pivotallyconnected to saidarm and having a stop associated therewith for engagingsaid upper brake shoe to eiect release of both of said shoes uponmovement ofI said. member out ofa given position, said stop beingnormally out of engagement with said upper brake shoe, a springassociated with said member tending to move said arm upwardly out ofsaid given position and to e ect set-l ting of said brake shoes, saidspring being ineifective upon engagement of said stop with said upperbrake shoe and a solenoid fixed to said base andhaving its plungerconnected to said arm at a point adjacenm the free end thereof.

9. .The combination with a brake drum and cooperating brake shoes of anoperating arm biased towards a given position, means operativelyconnecting said 'arm to said yshoes to provide for release of the latterupon movement ofthe former out of said 35 'given position, andy springmeans tending to move said arm out of said given position and to leiiectsetting of said brake shoes, said sprin means being ineffective after aslight initlal Vmovement of .saidl armloutof said given position.

10. The combination with va brake vand coo rating brake shoes ofoperating means or said shoes including an arm g of said shoes andmovable in' an op or limiting movement ofr said arm in the formerdirection, spring means for elfecting setting of said shoes, said springmeans 1 tending-to` move said arm out ofengagement slight initialvmovement; of said arm Vout ci J engagement with said stop, andelectromag- In witness whereof, I scribed my name. J HOWARD E. HODGSON.

biased to move inonek direction to eiiect set- `9|;

tln positie direction for release thereof, a stop i with said stop andbeing ineifective Vupon a los ave hereunto subl p DISCLAIMER. v v1,532,13;8.-Howard E'. Hodgson, Milwaukee, Wisconsin. ELECI'ROMGNETICBRAKES.

Patent dated April 7 1925. Disclaimer filed October 13, 1926, bytheassignee,

The UutleiHammer M fg. 0'0.4 I l Hereby makes this disclaimer 'to thatpart of the. claims in said specification which is in the followingWords, to wit:

1.l The combination with a brake drum and cooperating bra-he shoes of aWeighted'l operating armtending to inove under the action of gravitytowards a given position, means operatively connecting said arm to saidshoes'to provide for the releasev othe latter upon movement of theformer out of said given position and spring means tendin to move saidarm out of said iven position and to effect settin of `said brake shoes,said spring means being ine of said arm ont of said given position.`

2. The combination with a brake drum and cooperating'brake shoes ooperating means for said shoes including a weighted arm tending to movein one direction under the action of gravity to effect setting of saidshoes and movable in an opposite ective after a. slight initial movementdirection for release thereof, a ixed stop for limiting movement of saidarm under the action of gravity, and spring means for. eiecting settingofsaid shoes, said spring means tending to in'ove said arin out-A ofengagement with said stop and being ineffective upon a slight initial,movement of said arm out of engagement withv lsaid stop. A j 3.Thecombination witha brake drum and cooperating brake yshoes ofoperating'L means'foi said shoes including a weiglitedaim tending tomovein one direction 'v under the action of gravity to effect setting ofsaid shoes and movable in an opposite'A direction for release thereof, afixed stop for limiting movement ofA said arm under, the actioir ofgravity, spring means for effecting setting ofl said shoes, said spring'rement with said stop and being inf l' means tending to move said armout of enga? effective uponl a slight initial movement of said arm outofengagement with' J`said i stop and an operatin solenoid connected tosaid arm. ';4. The combination with a. brake drum and cooperatingpivoted brake shoes arranged on opposite sides thereof, of a weightedoperating arm ivotally connected to one of said brake shoes and tendingto move Iunder the action ci) gravit to a given. position, meansconnecting saidarms to the 1other of saidbrake shoes, an providing forrelease of said ',shoes from said-drum upon movement' of said arm out ofsaid given position, a spring. associated with said meansV andV tendingto move 'said arm out ot said (given position and to eiect setting ofsaid brake shoes,'and a solenoid for.

moving sai arm out offsaid'given position for release of brake shoes. p5. The combination with a brake drum having opposed pivoted brake-shoesassociated therewith, of an operating arm' pivotally connected toone ofsaid brake shoesand tending to move under the action of gravity to aiven position, an operatconnection between said arm and the other ofsaid bra e shoes, said connection providing forrelease of said brakeshoes upon movement of said anni out of said given position, springmeansassociated 'with-said operating connection tending to move said arm outof said given position and to effect setting of said brake'hoes, saidarm being uninfli'ienced by said spring'means upon movement 'thereof outvof l' A.saidgiven position and an operating solenoid associated'vvithsaid arm t0. effect release of saidbrake shoes. j t

9. Thel combination with a brake drum and cooperatinur brake shoes'ofan`operatmgarm biased toward a given -position,. means operativelyconnecting ,said arm to said shoesftoprovide for release of the latterupon movement of the' former out of said given' estion', and^'sfpringmeans to fmoveY said armout of saidgivenv f position an to eiectj "gjofsaid brake" shoes, said spring means being ineffective 'after a slightinitial move ent o f said arm out of said givenpsition.

` o fsaid shoes and movable inanopV .sto o 10.Thecombination'visiti-ival brake drum and cooperating Yalie shoesof'operatmeans for said shoes including an arm biased to move in onedirection 'to eii'ect r-liiniting movement of said arm in ite directionfor release thereof, a e `former 'directongspring meansforl -g 'cf ofsaid shoes, said spring means tendingtomovejsaid arm oiitof engagementwith said stop and bein ineffective upon a', slight initialmovementbf`:said*ai'nrout of engagement withi said stop, andelectromagneticvineans 'for operat'-

